Implantable analyte sensors that are placed in the subcutaneous tissue or other soft tissue sites must develop and sustain a stable biointerface that allows the continuous and timely transport of analytes across the interface between the tissue and the device. For example, in the case of a glucose sensor, glucose must be able to freely diffuse from surrounding blood vessels to a membrane of the sensor. Glucose sensors may be implanted in the subcutaneous tissue or other soft tissue. Such devices include glucose oxidase based amperometric sensors that sense glucose for weeks, months or longer after implantation.
While the utility of such devices for glucose sensing has been demonstrated, the consistency of function for such devices is not optimal. For a particular device, the sensor may, for example: 1) fail to function (namely, fail to track glucose effectively) in a stable manner during the first few weeks after implantation; 2) not work at all during the first few weeks, but subsequently begin to function in a stable manner; 3) function well during the first few weeks, lose function, then regain effectiveness or never recover function; or 4) work immediately, and continue to function with high accuracy throughout the course of a several month study.
Glucose sensors with improved acceptance within the host tissue and decreased variability of response are required for reliable functionality in vivo. Accordingly, the present invention discloses systems and methods for providing this improved functionality and consistency of analyte sensor in a host.